Final answer:
DNA nucleotides and RNA polymerase bind to the promoter region during the initiation stage of transcription, where RNA polymerase starts synthesizing mRNA.
Step-by-step explanation:
DNA nucleotides and RNA polymerase bind to the promoter region of DNA during the initiation stage of transcription. In this first stage, the enzyme RNA polymerase recognizes and binds to a specific DNA sequence known as a promoter. This event signals the DNA to unwind, allowing RNA polymerase to read the DNA bases and begin synthesizing a strand of mRNA with a complementary sequence of bases. Although the promoter facilitates the start of transcription, it is not included in the resulting mRNA.